Isotopic tracers will be used to examine the nature and reversibility of the effects of radiant energy upon lens, cornea and conjunctiva. Alterations in DNA, RNA, protein, mucopolysaccharide and proteoglycan metabolism induced by UV radiation will be monitored by means of autoradiograpy of ocular tissue. An evaluation of the ability of near UV to induce unscheduled DNA synthesis or alter patterns of scheduled DNA synthesis in the anterior cye will be undertaken to determine the potential for genetic damage from this type of radiant energy. this evaluation, taken with the results of proposed studies of alterations in cell turnover and migration will establish, at the molecular level, the permanence and severity of any damage that is induced. The research design should elucidate the effects of the type of radiation that man might experience in his daily life and which might result in ocular damage via cumulative actions over the individual's lifetime. The effects of far UV radiation will also be examined in both young and old animals and in strains of animals that are susceptible or resistant to corneal cancer. This experimental design will therefore contribute to our understanding of the mechanisms involved in both aging and cancer.